Operating rod for electric switches



March '25, 1952 J, RANK ET AL 2,590,765

OPERATING ROD FOR ELECTRIC SWITCHES Filed Aug. 16, 1950 Inventors:

Edward J. -F'Tam k,

Cyril W. Driver",

T heir Atfiorneg.

Patented Mar. 25, 1952 STATES OFFICE The invention relates to the operating connections of circuit breakers, switches, or other electrical devices, particularly of the high. voltage type. having a thrust rod formed of insulating material to serve the dual functions of operating a high voltage movable conducting member while effectively insulating the operating. mechanism therefrom.

Operating rods for actuating switch blades and the like movable conducting parts of electrical devices must, possess adequate insulating properties so that the "live'parts are adequatelyinsu lated "from, the actuating mechanism which usually is at ground potential. Furthermore, whensuch' blades are required to move at high spe f df and carr'zrfv heavyjcurrents, such rods must,

possess high/mechanical strength. Where such rods are, relatively short, it is usual to arrange themso they operate in compression for withstanding their heaviest duty which, in circuit breakers, would be when closing against possible'heavy short circuits. Although conventional operating rod materials, such as maple, laminated wood, and some suitable insulating compounds may have appropriate strength, they may not in themselves constitute good bearing materials for their end connections. Accordingly, it is common practice to rivet metal plates thereto at the ends so as to constitute strong metallic connectors or couplings, which are well abl to withstand any high bearing pressures encountered at the coupling pins. In many cases, an eyebolt or other adjustable device would be screwed into one of these metal end members or ferrules for providing longitudinal adjustment for the rods whereby to'achieve proper closed contact conditions, or for adjusting the several rods in a multi-phase breaker so that they all have approximately the same loading in the closed. position. Because such metal-reinforcing end members invariably extend inwardly from the coupling pins, the effective insulating length of the operating rod is thereby decreased by a corresponding amount. Thus, in many compact electrical switches, the effective insulating length of an operating rod is frequently a critical factor in. deciding the space oi the rodrby extendingohe end (or both) {beyond its, couplin po nt nd t mby' eans of a e i li co p ing Mer enaries). prleierab of m tal. ton

7 Claims. (01. 209 15 necting back to the coupling point. Such coupling means are rigidly. affixed to the overextended end .oftheinsulating rod while the return portion thereofipivotally connects, with a pin or the like, to the movable conducting member;.or, if provided at the opposite end of the rod,. to the actuatin member thereat. In employing the rod lprimarily as a thrust member, the metallic return couplin g" may conveniently be designed as a light tensional structure.

Because suehflovershoqting ,of the rod end renders it more accessiblebybringing it more intothe open, we, therefore, as another aspect of our inventionfprovide means thereat for adjusting or varyingthe effective rod length, such means comprising a cooperating portion of the coupling structurepi iided at this, extended area ofthe rod;

Accordingly, oneobiectof the present invention is to'provide an insulating thrust, rod operatively interconnecting a; movable conducting member and, an actuating element of the operating mechanism vtherefor at a different potential, whichrod is elongated beyond its coupling point a d then 'r tiirne ou led thereto so as to enable the overall insulating length and consequently the voltage creep'age length of the thrust rod to be increased without however, increasing the c ua s nee etween t ecoupli s nt o the movaloleflconducting "member and the actuatng elem n of th .Q erat na m c ani Another object is to provide such an elongated suletir ea hru .mdwhereinth return o pling ahas. ineqrnerate he e i means for adjusting the efiective rodlength, and for it thereaf terilocking the couplingmeans in its final diust dpo 1 herl b and advan a s of the invention will appear' in the following description of theaccompanying drawing in which Fig. 1 is a sidefvi'ew of 'a typical high voltage circuit breakhe enclosing casing broken an improved elongated ble' 'pe tin rod embodying the present enlarged partial side view h hedetailsof construction h I, 11 la ngrod and its adjustable couplin arrangem ntjshownin Fig. l; and Fig. '3 ,is a cross sectlohal view of the arrange m t Sh gi l isf rr sto i -.1 ,v h h volta power c r cult breaker indicated generally by the reference rac er. l i lQW i, o t us emov type for metal lad witchgear application pro: vi h. m. lvl g ouete rat n l i which may be in the, form ,of a

solenoid or other suitable operating device of sufficient power to close the circuit breaksr Ill. The closing and opening forces exerted by the operating mechanism II may be transmitted to the clevis type crank I2 through any suitable form of motion converting and trip-free latching mechanism housed in compartment I3. The crank I2 is pivotally connected to an elongated insulating operating rod I4 having the adjustable coupling of the present invention for operating the conducting switch lever I5 that is pivotally mounted on a pin I6 carried by structural member I! and supported on the high voltage insulator I8. Conventionally, the circuit breaker III is a polyphase device so that it will be understood that the single operating mechanism I I may have coupled thereto a plurality of switch levers I5usually threeonly one of which is shown. The conducting switch lever or member I5 is normally at a high potential relative to operating mechanism I I and is shown interconnected by the electric bushing conductor I9 with one of the disconnect terminals 20 of the removable circuit breaker Ill, and is provided with main contacts 22 and arcing contacts 23 as well as the cooperating impulse piston means 24 that aids in effectively extinguishing the are occurring upon the interruption of the circuit. However, the improved operating rod of the present invention may be employed with equal advantage for operating any high voltage conducting member.

As more clearly shown in the enlarged view of Figs. 2 and 3, the conducting switch lever comprising a pair of spaced blade members I5 is provided with extended portions I5 which constitute a projecting clevis, between which the lower end of the insulating operating rod I4 projects in spaced-apart relation for increasing the voltage creepage length and insulation of the rod. A thrust-transmitting return clevis coupling 26, preferably a suitably formed metallic member, has the ends thereof pivotally coupled to the ends of the switch lever extensions I5 by means of the cooperating thrust-transmitting pin 21. An enlarged and elongated slot 28 is provided centrally in the operating and insulating rod I4 for at all times clearing the pin 21 therein in spaced-apart relation with both ends and sides of the slot during actual operation as well as when making adjustment of the thrust rod I4 relative to the thrust-transmitting clevis coupling 26 so that the operating length may be varied in the manner described below.

An'adjusting screw 30 projects axially from the elongated projecting end of the rod I4 so as to extend through the opening 3| formed in the center of the thrust-transmitting clevis coupling 26 with the adjustable clamping nuts 32 and 33 on opposite sides of the clevis. The adjusting screw 30 is fixedly attached to the end of rod I4 by means of the integral clevis head 35 thereof that is secured in place as by a rivet or rivets 36.

Thus, with the end of the insulating thrust rod I4 projecting in spaced-apart relation transverse the end of the conducting switch lever I5 and in central spaced-apart relation with the pivotally attached thrust-transmitting clevis or coupling 26, actual contact of the rod with the switch blade may be avoided so that creepage distance is thereby increased. Also the effective operating length of the rod I4 may be readily varied by simply turning the nuts 32 and 33 sufiiciently to insure proper operating of the conducting lever I5 to a desired predetermined position after which they are securely locked back in place. The slot 28 is made long enough to provide sufllcient clearance of pin 21 therein even when making extreme adjustments to effeet the proper engagement of the main contacts 22 and the arcing contacts 23 of the circuit breaker by the operating mechanism II. Thus, the overall insulating length of the rod I4 is substantially increased, thereby correspondingly increasing the voltage creepage distance and insulation provided by the operating and insulating rod I4 without, however, requiring any increased spacing between the coupling points of the movable switch lever I5 and the actuating crank I2 of itsoperating mechanism II. It will be understood that the improved elongated rod and its return clevis may be applied to either end of thrust rod I4 as desired for most convenient adjustment.

What we claim as new and desire to secure by Letters Patent of the United States is:

1. In combination, a conducting operating lever, a thrust-transmitting coupling member pivotally connected with the lever, an operating thrust rod formed of insulating material having one elongated end thereof projecting transverse the operating lever in predetermined spaced-apart relationship with the thrust-transmitting memher, and means for rigidly connecting the projecting end of the rod with the thrust-transmitting member.

2. In combination, a conducting operating lever, a thrust-transmitting coupling member pivotally connected with the lever, an operating thrust rod formed of insulating material having one elongated end thereof projecting transverse the operating lever in predetermined spacedapart relationship with the thrust-transmitting member, and means for rigidly connecting the projecting end of the rod with the thrust-transmitting member, said thrust-transmitting coupling member including lockable adjustable means for varying the effective operating length of the thrust rod.

3. In combination, a movable conducting blade member, a clevis coupling member having its ends pivotally connected with the end of the conducting blade, an operating rod formed of insulating material and having one end thereof projecting beyond the operating blade along the axis of the clevis coupling, and means including an adjusting screw for operatively connecting the projecting end of the rod with the center of the clevis coupling.

4. In combination, a movable switch member, a clevis coupling formed to cooperate with the switch member, an interconnecting pin extending through the ends of both member and coupling, an operating rod formed of insulating material and having one end thereof projecting transversely beyond the switch member along the axis of the clevis coupling and provided with a slot for clearing the pin therein and means including an adjusting screw for operatively connecting the projecting end of the rod with the center of the clevis coupling.

5. In combination, a conducting switch lever comprising a pair of blades, a clevis coupling formed to cooperate with the ends of the blades, an interconnecting pin extending through'the ends of the blades and the coupling, an insulating operating rod having one end thereof projecting transversely through the blades along the axis of the clevis coupling and provided with a slot for clearing the pin therein, and means including a screw projecting axially from the end 5 of the rod through the center of the elevis coupling for adjustable interconnection thereof.

6. In combination, a conducting switch lever the spaced blades thereof comprising a clevis, a second clevis having the ends thereof pivotally coupled with the ends of the blade clevis, an interconnecting pin extending through the ends of both clevises, an insulating operating rod having one end thereof projehting transversely through the blade clevis along the axis of the second clevis and provided with a, slot for clearing the pin therein, and an adjusting screw extending through the center of the second clevis and having clamping nuts onfopposite sides thereof and provided with a clevis head for securing the projecting end of the rod therein.

7. An insulating operating rod arrangement having in combination a movable electrical conductor, the operating member formed of insulating material having one end thereof elongated so as to project transversely beyond the movable conductor in spaced-apart relation therewith to increase the virtual creepage length of" the insulating operating member, and a thrust-transmitting coupling member provided with means for pivotally connecting it with said movable conductor and with means for rigidly connecting it with said insulating operating member.

EDWARD J. FRANK. CYRIL W. DRIVER.

REFERENCES CITED The following references are of record in the file of this patent:

Miller Nov. 17, 1931 

